*HEADING
 BEAM ELEMENTS: MODEL CHANGE VERIFICATION, ELASTIC MATERIAL
*RESTART,WRITE
*PREPRINT,MODEL=YES,HISTORY=NO
**
** TEST 1: PIPE21
**
*NODE,NSET=NALL
1, 20.,10.
2, 25.,15.
3, 30.,20.
11,40.,10.
12,40.,15.
13,40.,20.
*NSET,NSET=LEFT
1,11
*NSET,NSET=RLEFT
1, 
*NSET,NSET=TLEFT
11, 
*NSET,NSET=MID
12, 
*NSET,NSET=RIGHT
13, 
*NSET,NSET=TIP
3,13
*ELEMENT,TYPE=PIPE21,ELSET=TEST1
1, 1,2
2, 2,3
11,11,12
12,12,13
*ELSET,ELSET=REFER
1,2
*ELSET,ELSET=TEST
11,12
**
** TEST 2: PIPE22
**
*NODE,NSET=NALL
101, 60.,10.
102, 65.,15.
103, 70.,20.
111, 80.,10.
112, 80.,15.
113, 80.,20.
*NSET,NSET=LEFT
101,111
*NSET,NSET=RLEFT
101, 
*NSET,NSET=TLEFT
111, 
*NSET,NSET=MID
112, 
*NSET,NSET=RIGHT
113, 
*NSET,NSET=TIP
103,113
*ELEMENT,TYPE=PIPE22,ELSET=TEST2
101,101,102,103
111,111,112,113
*ELSET,ELSET=REFER
101,102
*ELSET,ELSET=TEST
111,112
**
** TEST 3: PIPE21H
**
*NODE,NSET=NALL
201, 100.,10.
202, 105.,15.
203, 110.,20.
211, 120.,10.
212, 120.,15.
213, 120.,20.
*NSET,NSET=LEFT
201,211
*NSET,NSET=RLEFT
201, 
*NSET,NSET=TLEFT
211, 
*NSET,NSET=MID
212, 
*NSET,NSET=RIGHT
213, 
*NSET,NSET=TIP
203,213
*ELEMENT,TYPE=PIPE21H,ELSET=TEST3
201, 201,202
202, 202,203
211, 211,212
212, 212,213
*ELSET,ELSET=REFER
201,202
*ELSET,ELSET=TEST
211,212
**
** TEST 4: PIPE22H
**
*NODE,NSET=NALL
301, 140.,10.
302, 145.,15.
303, 150.,20.
311, 160.,10.
312, 160.,15.
313, 160.,20.
*NSET,NSET=LEFT
301,311
*NSET,NSET=RLEFT
301, 
*NSET,NSET=TLEFT
311, 
*NSET,NSET=MID
312, 
*NSET,NSET=RIGHT
313, 
*NSET,NSET=TIP
303,313
*ELEMENT,TYPE=PIPE22H,ELSET=TEST4
301, 301,302,303
311, 311,312,313
*ELSET,ELSET=REFER
301,302
*ELSET,ELSET=TEST
311,312
**
**  REMAINDER OF INPUT DECK SAME FOR ALL TESTS
**
*ELSET,ELSET=EALL
TEST,REFER
*BEAM SECTION,SECTION=PIPE,TEMPERATURE=GRADIENTS,MATERIAL=ELAS,ELSET=EALL
1.0,.05
0.,0.,-1.
*NORMAL
TEST,LEFT, -1., 0.,0.
TEST,MID,  -1., 0.,0.
TEST,RIGHT,-1., 0.,0.
*AMPLITUDE, NAME=RAMP
0.,0., .004,1.
*MATERIAL,NAME=ELAS
*ELASTIC
30.E6, .3
*EXPANSION
1.E-6, 
*DENSITY
7.338E-4, 
*INITIAL CONDITIONS,TYPE=TEMPERATURE
NALL,70.,0.
**
**
*STEP,NLGEOM
 STEP #1: DISPLACE TEST SPECIMEN SO FINAL SHAPE IS
          IDENTICAL TO INITIAL SHAPE OF REFERENCE ELEMENT 
*STATIC
0.25,1.
*PRINT,MODEL CHANGE=YES
*BOUNDARY,OP=NEW
LEFT,1,2
RLEFT,6
TLEFT,6,6,-.7853982
RIGHT,1,1,10.0
RIGHT,2,2,0.0
RIGHT,6,6,-.7853982
MID,1,1,5.0
MID,2,2,0.0
MID,6,6,-.7853982
*OUTPUT,FIELD,FREQ=0
*NODE PRINT,FREQ=999
RF, 
*EL PRINT,POSITION=CENTROID,FREQ=999
1,
S,E
*NODE FILE,FREQ=999
RF, 
*EL FILE,POSITION=CENTROID,FREQ=999
E, S
*END STEP
**
**
*STEP,NLGEOM
 STEP #2: REMOVE TEST ELEMENTS
*STATIC
1.,1.
*MODEL CHANGE,REMOVE,TYPE=ELEMENT
TEST,
*END STEP
**
**
*STEP,NLGEOM
 STEP #3: ADD TEST ELEMENTS BACK IN STRAIN-FREE
*STATIC
1.,1.
*MODEL CHANGE,ADD=STRAINFREE,TYPE=ELEMENT
TEST, 
*BOUNDARY,OP=NEW,TYPE=VELOCITY
LEFT,1,6
*END STEP
**
**
*STEP,NLGEOM
 STEP #4: APPLY LOAD TO BOTH ELEMENTS 
*STATIC
0.25,1.
*DLOAD
TEST,GRAV,150.,0.,1.,0.
REFER,GRAV,150.,0.,1.,0.
*END STEP
**
**
*STEP,NLGEOM
 STEP #5: REMOVE TEST ELEMENT
*STATIC
.25,1.0
*MODEL CHANGE,REMOVE,TYPE=ELEMENT
TEST,
*OUTPUT,FIELD,FREQ=1
*ELEMENT OUTPUT
 S,E
*NODE OUTPUT
 RF,
*END STEP
**
**
*STEP,NLGEOM
 STEP #6: ADD TEST ELEMENTS BACK IN WITH-STRAIN
*STATIC
.25,1.0
*MODEL CHANGE,ADD=WITHSTRAIN,TYPE=ELEMENT
TEST,
*END STEP
**
**
*STEP,NLGEOM
 STEP #7: APPLY THERMAL LOAD
*STATIC
.25,1.0
*BOUNDARY,OP=NEW,TYPE=VELOCITY
TIP,1
LEFT,1,6
*TEMPERATURE
NALL,100.,20.,0.
*EL PRINT,POSITION=CENTROID,FREQ=999
1,
S,THE,E,TEMP
*EL FILE,POSITION=CENTROID,FREQ=999
S,THE,E,TEMP
*END STEP
**
**
*STEP,NLGEOM
 STEP #8: FREQUENCY EXTRACTION
*FREQUENCY,EIGENSOLVER=LANCZOS, SIM=NO
36,,,,4,12
*BOUNDARY,OP=NEW
LEFT,1,6
*EL PRINT,FREQ=0
*NODE PRINT,FREQ=0
*MODAL FILE
*OUTPUT,FIELD,VAR=PRESELECT,FREQ=1
*OUTPUT,HISTORY,FREQ=1
*END STEP
**
**
*STEP,PERTURBATION
 STEP #9: MODAL DYNAMIC
*MODAL DYNAMIC
.0004,.004
*CLOAD
TIP,2,150.
*NODE PRINT,FREQ=999
RF, 
*EL PRINT,POSITION=CENTROID,FREQ=999
1,
S,E
*NODE FILE,FREQ=999
RF, 
*EL FILE,POSITION=CENTROID,FREQ=999
E,S
*END STEP
**
**
*STEP,PERTURBATION
 STEP #10: STEADY-STATE DYNAMICS, MODAL BASED
*STEADY STATE DYNAMICS,INTERVAL=RANGE
1000., 
*CLOAD
TIP,2,150.
*NODE PRINT,FREQ=999
RF, 
*EL PRINT,POSITION=CENTROID,FREQ=999
1,
S,E
*NODE FILE,FREQ=999
RF, 
*EL FILE,POSITION=CENTROID,FREQ=0
*END STEP
**
**
*STEP,PERTURBATION
 STEP #10: STEADY-STATE DYNAMICS, DIRECT
*STEADY STATE DYNAMICS,DIRECT
1000., 10000., 5
*BOUNDARY,OP=NEW
LEFT,1,6
*CLOAD
TIP,2,150.
*NODE PRINT,FREQ=999
RF, 
*EL PRINT,POSITION=CENTROID,FREQ=999
1,
S,E
*NODE FILE,FREQ=999
RF, 
*EL FILE,POSITION=CENTROID,FREQ=0
*END STEP
**
**
*STEP,NLGEOM
 STEP #11: DYNAMICS
*DYNAMIC
.0004, .004
*BOUNDARY,OP=NEW,TYPE=VELOCITY
LEFT,1,6
*EL PRINT,POSITION=CENTROID,FREQ=999
1,
S,E
*NODE PRINT,FREQ=999
RF, 
*CLOAD,AMP=RAMP
TIP,2,150.
*END STEP